Weight training can be an effective way to burn calories, lose fat and increase your strength -- it's not just about building big muscles. According to a report from the University of Illinois, using free weights has more benefits for everyday life and recruits extra stabilizing muscles too. A free weight workout doesn't have to last for hours and while there's no single best approach, there are several guidelines that can provide you with a short, but highly effective workout.

Exercise Selection

To make the most of your time in the gym, choose compound exercises that work multiple muscle groups simultaneously. These include squat and deadlift variations, lunges or step-ups, bench presses, dumbbell presses and rows. Because they work more muscle groups, these exercises burn more calories than isolated muscle exercises, claims Rachel Cosgrove, trainer and owner of Results Fitness in California. According to the American Council on Exercise, compounds are also the best choice for building muscle mass.

Supersets

Supersetting can speed up your workouts without negatively impacting your training quality. A superset involves performing two exercises back to back, without taking any rest in between them. Not only does this save time, but supersets have the added bonus of increasing muscle growth and growth hormone production, which aid fat loss, writes personal trainer Nick Nilsson on CriticalBench.com. Superset your dumbbell rows with bench presses, squats with deadlifts or shoulder presses with lunges.

Sets, Reps and Structure

Different repetition ranges suit different goals. Sets of one to five reps per set are best for strength training, six to 12 reps per set builds muscle, while higher reps are better suited for muscular endurance training. Base your training around the rep range that best supports your goal. You may find that by keeping rest time to a minimum in short workouts you struggle to lift as much weight as you otherwise would in a regular workout with longer rest periods. Your body will soon adapt, but you may need to decrease your weight in the meantime.

Considerations

Train two to three times per week, working your whole body in each session. The weights you use should be challenging, but you should be able to complete all the reps with good form. Aim to add more weight or reps to every exercise each session. How long you spend in the gym depends on your schedule, but try to get through at least four exercises in each workout -- two upper body and two lower body moves. If you're really pushed for time, superset three or four exercises back to back and always ask a qualified trainer for help if you're unsure of any techniques.

About the Author

Mike Samuels started writing for his own fitness website and local publications in 2008. He graduated from Peter Symonds College in the UK with A Levels in law, business and sports science, and is a fully qualified personal trainer, sports massage therapist and corrective exercise specialist with accreditations from Premier Global International.